CRPSC 70 Cereal and Legumes

Corn Growth and Development

o Corn of maize (Zea mays L.) is one of the important crops in the Philippines. About 20% of the population from Visayas and Mindanao consume corn as staple food in the form of white corn grits. It is the major source of income and employment of over a million farmers, majority of whom fall below the poverty line. At least two-thirds of our corn supply is used for livestock and poultry feeds and as raw materials in the manufacture of starch, syrup, oil and other starch derivatives. o Corn can be grown as monocrop and/or as an intercrop under coconut trees, fruit trees and others. o Zea is a genus of the family Graminae (Poaceae), commonly known as the grass family (Hitchcock and Chase, 1971). It is cultivated globally being one of the most important cereal crops worldwide. Maize is not only an important human nutrient, but also a basic element of animal feed and raw material for manufacture of many industrial products. The products include corn starch, maltodextrins, corn oil, corn syrup and products of fermentation and distillation industries. It is also being recently used as biofuel (Dept. of Biotechnology,undated ). o Corn can grow in soil temperatures that are warm. o The most desirable soil for corn production is deep, medium texture, high organic matter, well drained with a high water holding capacity and capable of supplying adequate amount of essential nutrients. This ideal soil would likely be a loam or silt loam on the surface with a silty clay loam to moderately permeable subsoil extending with a slight change to a depth of at least 120 cm. it should have a pH value ranging from 5.3 to 6.0 and percent base saturation of 75%. The Bray no. 2 soil P-test value ranges from 16 to 20.5 ppm (PCARRD, 1981). o Next to palay (rice), corn is considered as the second most important crop in the Philippines. The country is engaged in the production of white and yellow corn, which comprises one third of the total corn area (DA-ATI, 2008)

Growth Stage of Corn

Growth stages may overlap in a field A growth stag for a field begins when at least 50 percent of the plants have reached or are beyond a certain stage.STRESS AND CROP YIELD LOSS At each growth stage of corn, certain aspects of management must be considered. Each stage has its own problems which may interfere with growth at that stage Problems include adverse soil conditions, weeds, insects, diseases, and other disorders. Problems that occur early in the season may contribute to the yield loss experienced at the end of the season during harvest.CRPSC 70 Cereal and Legumes

Leaf collar method

o The collar is where the leaf blade visually breaks away from the sheath and the stalkThe number of visible collar = vegetativegrowth stage (V stages

Leaf collar method

Leaves still in the whorl- DO Not count these leaves Leaves with a visible collar COUNT these leaves

STEP 2 Soil Testing

o To determine specific fertilizer requirements, it is best to submit soil samples for

analysis to the nearest DA soils laboratory. A quick analysis can be done right in the farmers field by mans of soil test kit (STK). o Soil Test also determines soil acidity. If pH is less that 5,3 liming should be done to correct pH. Depending on the type of soil, apply calcium carbonate (CaCo3) at the rate of 0.4 to 1.2 tons per 0.1 pH unit below 5.3. Apply lime 30 days before planting. The required amount is broadcast and harrowed in.

STEP 3 Land Preparation (30 days before planting)

o If your soil is poor, apply 5-10 tons compost per hectare before plowing. Plow the soil at least 16 centimeters (cm) deep to provide good soil condition and tilt for root development. It also minimize weed problem. Plow once and harrow once.CRPSC 70 Cereal and Legumes

STEP 4 Preparation Furrows (1 day before planting)

o Make furrows at 75 cm spacing and about 8 cm depth

STEP 5 Application of basal fertilizer (day of planting)

o Apply basal fertilizer in the furrows at the rate of 4 bags of complete fertilizer (14- 14-14) per hectare. This provides 28 Kgs each Nitrogen (N), Phosphorous (P205) and Potassium (K2). Cover fertilizer with soil to avoid contact with seed. When using organic fertilizer, provide equivalent amount of nutrient. (Note that actual rate of fertilizer application should be initially based on soil analysis).

Step 6 planting (day of planting)

o Plant 3 seeds per hill, spaced 5 cm apart

o STEP 7 Cultivation, weed Control and Thinning of Seedlings o (12 days after planting) o Undertake shallow cultivation and spot weeding to control weeds. Thin seedlings to 2 per hill. To further control weeds, another shallow cultivation can be done.

STEP 8 Sidedressing of Nitrogen Fertilizer (25 days after planting)

o Side-dress with 2 bags urea (45-0-0) per hectare

STEP 9 Pest Management (Whorl Stage)

o If available, first use Trichogramma biocontrol of corn borer. The first release is done at 40-50 cards per hectare, 20-30 days after planting. The second release at 40-50 cards per hectare is done 2 to 3 days after the first release if parasitism of corn borer egg masses is below 20%. Simply hang a Tricho card near the base of one of the fully expanded leaves of a plant. Hang cards on plants in strategic spots of cornfield. If Trichogramma are not available, control corn borer by means of chemical pesticides. At mid-whorl stage (25-35 days after planting), when 40-50% show infestation, apply carbofuran granules onto the whorl of affected plants; or spray any of the following insecticides: endosulfan, methomyl, monocrotophos or carbaryl. This can also control earworms and cutworms.

STEP 10 Pest Management (Tasseling Stage)

o When the corn borer infestation persists, employ a combination of detasseling

and chemical control. Simply pull out the tassel (not break off) from the peduncle of plants of 3 rows for every 4 rows. Corn plant is ready for detasseling when one-half to three-fourth of the tassel (before pollen shedding) has emerged.

Note: Do not detassel all the plants; leave one row for every 4 rows with intact tassels.Bring detached tassels out of the corn field, these may be used as cattle/Carabaofeed if not sprayed with insecticides. If plants with tassels are heavily infested, spray withany of the recommended insecticides in Step 9.CRPSC 70 Cereal and Legumes

STEP 11 Harvesting (100-105 days after planting)

o Corn crop is ready for harvest 100 days after planting during dry season and 105 days after planting during wet season. As a guide, corn can be harvested when corn kernels are glazed and black layer is formed. This can be determined by detaching a few corn kernels from the cob.

PRODUCTION GUIDE ON SUPER SWEET CORN

o Recommended Varieties o SUGAR 73, 75 68-70 DAP (Maturity)

CROPPING SEASON o This variety of sweet corn is not the usual sweet corn. It is a hybrid variety. It produces almost the same sizes of ears, resistant to pests and the sweetness remains for 3 days. It tolerates heav rain, unless flooded and during dry season thus it is called all season variety.

SOIL REQUIREMENT o Sweet corn grows in different kinds of soil but good drainage should be assured to avoid water logging that may damage any plant roots. However, loam soil is preferred for better results

PLANTING o Planting is done with the distance 75 cm between rows and 20 cm between hills, sowing one seed per hills, sowing one seed per hill with the depth of 2 cm. Seed will be covered thinly with soil. The area of 1,000 sq. m. contents 5,000 corn plants or 50,000 corn plants per hectare.

FERTILIZATION o The soil must be analyzed by the Bureau of Soil for appropriate fertilizer recommendation. However, without analysis, the recommended rate is used: basal application of 4 bags of 14-14-14 per hectare will be applied in the furrowCRPSC 70 Cereal and Legumes

before sowing the seed and be covered thinly with soil to avoid seed to contact with the fertilizer. o Second application or sidedressing should be done 25 DAP using 2 bags of urea per hectare. Third application: 2 bags of urea (45-0-0) per hectare at 45 DAP.

IRRIGATION o If the soil is not enough, irrigation should be done to obtain soil moisture up to 5 cm depth. This will be done 7-10 days interval and at 2-5 days before fertilization.

PEST CONTROL o In order to control pests, mix 1 bag of Furadan 3G fertilizer during basal application. As precautionary measures, water hand gloves or use any protective covering to avoid having direct contact with the chemicals. Inspect the field every day and spray Vertex of Basudrin 400 EC if pest occurs. Repeat every 10 days. Seeds are coated with insecticide and fungicide to prevent Downy Mildew. These varieties are also resistant to blight and leaf rust.

WEED CONTROL o Spray 1-2 liters of Herbadox to control Aguingay and 1-2 kg gesaprim 80WP for broadleaves, sedges and other grasses that cannot be eradicated by herbadox. These herbicides should be sprayed 1-2 DAP. However, weed control should have started during thorough land preparation in order to attain a clean field up to 30-40 DAP.HARVESTING o Harvesting should be done 68-70 DAP or 20 days after silking. It should be done early in the morning until 9:00 in the morning and at 4:00 in the afternoon to avoid losing its sweetness. This is also true and applicable to type of sweet corn.